The present disclosure is generally directed to processes for the reclamation, remanufacture, and reuse of waste or spent toner compositions, including color toner compositions. More specifically, the present disclosure relates to processes for the reclamation and remanufacture of used toner compositions, including color toner compositions, comprising reformulating waste toner particles with new, unused or pristine toner compositions, and reuse of the resulting toner particles with, for example, carrier particles in two component xerographic developers.
Recycling or reclamation processes of xerographic developers and toner compositions, such as toner fines, are known in the art. The prior art processes are generally directed to reclaiming and reusing waste toner particles within the confines of a printing machine, or alternatively, reclaiming and reusing waste toner particles arising from a toner manufacturing process within the confines of a toner manufacturing facility. Alternatively, known processes generally require that the waste toner particles have the same or substantially similar composition to the new toner composition with which the used toner particles are mixed.
The present disclosure, in contrast, provides, in embodiments, processes for recycling, reuse or reclamation of waste toners comprising reclaiming waste toner particles comprising of different colors, for example, from one or more printing machines in field use; co-locating the reclaimed waste toner, for example, in a reprocessing, or manufacturing facility; screening the waste toner to remove debris; meltmixing the screened waste toner in admixture with pristine or fresh toner constituents or ingredients; and processing the resulting melt mixed product in a conventional fashion, for example, grinding and classifying, to provide remanufactured toner particles which contain reclaimed or waste toner, for example, in amounts of from about 1 to about 25 weight percent, and which remanufactured toner when installed in a printing or copying machine has xerographic performance properties that are substantially the same as those obtained from toner prepared entirely from fresh toner constituents. The present disclosure, in embodiments, is applicable to reclaiming and reusing waste toner compositions that include different color toner particles, and where the waste toner compositions may be of different chemical composition.
U.S. Pat. No. 4,054,381 discloses a toner filter arrangement adapted for use in a cleaning station of a xerographic reproduction machine whereby foreign matter and other contaminates are removed from residual toner prior to its collection in a disposable or re-use container or return to the developer station. The filter arrangement comprises a housing having an input opening through which removed toner enters and an output opening through which filtered toner exits by gravity feed.
U.S. Pat. No. 5,200,788 discloses a brush auger reclaim filtration assembly incorporated into an open ended chamber contained in a printing machine. The brush auger is a toner reclaim filtration device that is rotatably mounted in the chamber to move toner and debris along a separating screen. Also contained in the housing is a mounted transport auger that rotates as it moves the reclaimed toner to the developer housing.
U.S. Pat. No. 4,494,863 discloses a toner removal device for removing residual toner and debris from a charge retentive surface after transfer of toner images from the surface. This device is characterized by the use of a pair of detoning rolls, one for removing toner from a biased cleaner brush and the other for removing debris such as paper fibers and kaolin from the brush. The rolls are electrically biased so that one of them attracts toner from the brush while the other one attracts debris. Thus, the toner can be reused without degradation of copy quality while the debris can be discarded.
These patents relate to an apparatus for reclaiming and re-use of waste toner particles within a printing machine and are not believed to embody removal of the reclaimed toner from the machine for remanufacture with fresh toner as in the present disclosure.
Other patents of interest include U.S. Pat. Nos. 5,272,034; 5,147,753; and 5,111,998, which patents relate to conventional toner manufacturing processes wherein there is generated a waste stream of toner particles, for example, coarse or fines, and which waste toner particles are returned or recycled into an earlier step or stage in the toner manufacturing process. These patents are not believed to contemplate removal of reclaimed waste toner from a printing machine for remanufacture with fresh toner as in the present disclosure.
The aforementioned references are incorporated in their entirety by reference herein.
Conventional xerographic development processes are relatively inefficient in the utilization of toner particles in various developers, for example, up to about 20 weight percent of the toner deposited on a photoreceptor in developing latent images is typically routinely recovered, such as by cleaning, as waste toner in a toner sump. As a result, a large amount (in the thousand to millions of pounds) of toner particles are introduced into the landfills.
In an extensive study of fresh or newly manufactured toner particles and waste toner particles, the principal difference observed was that the waste toner contained, for example, paper fibers and other extraneous debris. Paper fibers and the like particulates can tend to charge to an opposite polarity from the toner particles and which lead to copy quality defects in, for example, background areas. The aforementioned U.S. Pat. No. 4,494,863, accomplishes “in-machine” electrostatic separation of particles of opposite polarity prior to return of the cleaned toner to the developer housing.
In view of the increasing costs and regulation associated with land fill and related waste disposal facilities, it is desired to recycle and to re-use waste toner particles in batch or continuous processes readily and conveniently at, for example, a central processing facility. Earlier attempts to recycle reclaimed toner particles by, for example, collecting waste toner, screening the collected waste toner to remove extraneous debris and agglomerates, conditioning the screened waste toner with surface additives, repackaging, and reusing the conditioned toner in a marking process, proved to be difficult and typically ineffective in reproducibly providing toner particles with the requisite triboelectric, conductivity, and flow properties necessary for high copy quality and high volume printing machine performance.
In this respect, at least U.S. Pat. No. 5,888,691 discloses a process for reclaiming, remanufacturing and reusing waste toner particles. The disclosed process comprises collecting waste toner, screening the collected waste toner, melt mixing the screened waste toner with a second toner, and grinding and classifying the melt mixed toner product.